Steam-power-plant control



Jan. 22 1924.-

J. w. DOBLE STEAM POWER PLANT CONTROL iledbec. 13. 1919 5 Sheets-Sheet 14 FIB-l L g'llllll' I r/ dwwooeze 7 4a, TTORNEYS.

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J. W. DOBLE swam rowan PLANT CONTROL Filed Dec. 13. 1919.

5 Sheets-Sheet 2 \4 ii an H INVENTOR Aw ATTORNEYS.

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'" J. W. DOBLE 5mm POWER PLANT CONTROL 5 Sheets$heet 4.

Filed De c. 13 1919 "AHTNEQSL INVENTOR;

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J. W. DOBLE STEAM POWER PLANT CONTROL Filed Dec. 13, 1919 s Sheets-Sheets .fIQ. El

WAHTNESS INVENTOR W4 J. M 00845 Qua M ATTORNEYS.

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JESSE W. DOBLE, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO DOBLE ORA-TORIES, SAN FRANCISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

STEAM-POWER PLANT CONTROL.

Application filed December 13, 1919. Serial No. 344,741.

To all whom it may concern: v

Be it-known that I, Jnssn W. DoBLE, a citizen of the United States, anda resident of thecity and county of San Francisco, State of California,have invented a certain new and useful Steam-Power-Plant Control, ofwhich the following is a specification.

The invention relates to the control of the fire in liquid fuel burnerswhen used in connection with steam boilers or other heat absorbingmedium containing devices and to the control of water supply to steamboilers. The objects of the invention are many, as

' will appear hereinafter.

One of the'objects of the invention is to provide a control system forliquid, ;fuel burners of heat absorbing mediumcontaining devices, inwhich the amount oi' volume of the lire is varied in accordance withchanges in temperature or pressure within the device.

Another object is to provide means for varying the fire whilemaintaining the proportion of air to liquid fuelin the combustiblemixture substantially constant, thereby providing an eiiicient andcompletely combustible mixture, regardless of the sizeoi the flame.

Another object of the invention is to vary the feed water intake inaccordance with variations in temperature or pressure or both within thesteam boiler. 1

The invention possesses many other objects and features of advantage,some of which, with the foregoing, will beset forth at length in thefollowing description, where I shall outline in full, that form of theinvention which I have selected for illustration in the drawingsaccompanying and forming part of the present specification. In saiddrawings, l have shown one specific embodiment of my generic invention,but it is to be understood that I do not limit myself to such form,since the invention as expressed in the claims may be embodied in aplurality of forms.

The drawings show the invention as embodied in a steam boiler controlsystem, but it is to be understood that the invention is not limited touse with steam boilers, but may be employed in connection with hot waterheaters, house heaters and other heat absorbing medium containingdevices. The

steam boiler shown in the drawings is particularly adapted for use onsteam propelled vehicles, such as trucks, tractors and automobiles, inwhich use widely varying steam demands are made on the boiler. In suchuse,

the control system operates to maintain, or

to tend to maintain, a substantially constant temperature and pressurewithin the'boiler. The fixed temperature and pressure may not beexceeded, although in instances of extremely heavy steam demand, thepremure or temperature may fall slightly. This control is accomplishedby variations in air and liquid fuel, forming the combustible mixtureand variations of the rate of admission of the feed Water. 7

Referring to said drawings:

Figure 1 is a diagrammatic representation of a steam boiler providedwith the control system of my invention.

Figure 2 is .side elevation of a combined steam boiler and engine, theboiler being partly broken away to disclose the burner construction. 1

Figure 3 is a vertical section through the blower chamber and pressurecontrol devices, also showing the air valve;

Figure l is a vertical section of the pres sure operated control device,taken on the line 4-4, Figure 3.

Figure 5 is a top view of the pressure operated control device with thecover plate removed.

Figure 6 is a vertical section of the pressure control device, taken onthe line 6-6, Figure 3.

The'steam boiler 2 is provided with a. coinbustion chamber 3 in whichthe fire burns and from which it discharges into contact with the boilertubes-4;. The liquid fuel for combustion is fed through a suitableconduit, 5 into the rapidly rotatable cup 6, from which it dischargesina spray. An

suitable liquid fuel may be employed, suc

as kerosene or distillate. The cup 6 is rotated by an electric motor 7and arranged on the motor shaft is a blower-8, enclosed in'the housing9. The air from the blower passes from the blower chamber into thechannel or passage 12, which is in thermal communication with thecombustion chamber, thence through the amag'e 13, surrounding thecombustion c amber, and thence into the chamber adjacent the rapidlyrotating cup, where it is mixed with the fuel spray, producingcombustible fuel mixture. The proportion of air and fuel is preferablysuch that a completely combustible mixture is produced. 4

The passage 12 is wider than the blower chamber 9 andvis connectedtherewith by a flaring passage 14. Arranged in the air passage andpreferably at the junction of the passage 14 with the passage 12 is a,damper or flat butterfly valve 15 which is operative to vary the area ofthe air passage and hence the volume of air passing into the combustionchamber. The valve 15 is caused to operate by variations in pressure inthe boiler, an increase in pressure above a predetermined pressurecausing the valve to move to constrict the air passage and a decrease inpressure from an excessive pressure causing the valve to move to openthe air passage. shaft 16 journaled in the casing, and secured to anextension of the shaft is an indicator 17 which shows the position ofthe valve.

Mounted on the blower casing, at one side thereof, is a cylinder 18having a bottom therein upon which the spring 21 bears. The cylinder isclosed at the top by a, head 22 having a; smaller cylinder 23 formedintegrally therewith. The cylinder 23 is pro vided With a nipple 24 forconnection with a steam zone in the boiler, so that steam under boilerpressure flows into the cylinder 23. Disposed in the smaller cylinder isa piston 25, having an extension 26 which projects through an aperturein the bottom of cylinder 23 and which rests on the bottom of thecylinder 27 The upper end of the cylinder is flanged and rests on orengages the upper end of the spring 21. The spring,

therefore, holds the piston 25 pre$ed up-' wardly, and when the steampressure exceeds the spring pressure, the piston is depressed. Securedto the piston is an adjustable rod 28, provided at its lower end with arack 29 in engagement with the gear 31 on the shaft 16. Depression ofthe piston for the limit of its movement closes the 0 valve 15, so thatpractically no air passes into the combustion chamber.

Means operated by an increas in pressure are also provided fordecreasing the fuel supply, the decrease of fuel supply varying with theincrease in pressure. Mounted on the other side of the blower casing isa chamber 32, into which extends the adjusta-ble length 'rod 33,provided on its lower end with a rack 34 in engagement with the 0 gear35 on the shaft 16. The rod 33 lies on the opposite side of the shaftfrom the rod 28, so thata, downward movement of rod .28 causes an upwardmovement of rod 33 and vice versa. Arranged in the casing 32 5 isarotary fuel valve 34' having inletand The Valve is mounted .on a

Learner) outlet connections 35 and 36 towhich the fuel conduit 5 isconnected. The valve is provided with a pin or projection 37 which liesin the groove of a collar 38 adjustably secured to the rod 33, so thatas the rod moves vertically, the valve is turned to vary the flow offuel. When the rod 33 is in its lower position, the valve is fully openand as the rod raises, the valve is turned to restrict the flow of fuel.The fuel valve is thus directly connected to the air valve, so that thesupply of air and fuel are simultaneously varied and in preferably thesame degree, so that a perfectly combustible mixture is always produced,regardless of the size of the flame. The fire is, therefore, varied byvariations in pressure in the boiler above a predetermined pressure.

Means operative by variations in pressure above a predeterminedpressure, are also provided for controlling the flow of feed water intothe boiler. Feed water is forced into the boiler by the pump 41 which ispump. The solenoid circuit isnormally open and means are provided forclosing the circuit when a predetermined excessive pressure is reachedin the boiler. Disposed in the casing 32 above the rod 33 are a pair ofnormally separated contacts disposed in the circuit of the solenoid 43.The upper contact 44 is stationary and is secured to the binding post45. The lower contact 46 lies immediately below the upper contact and ismounted on a metallic lever 47 pivoted to the shank 48 of the bindingpost 49. The lever 47 is disposed above the end of the rod 33 and ispressed downward by a spring 51. When the rod 33 is moved upward, due toan increase in boiler pressure, it contacts with the insulator pad 52 onthe lever 47 and raises the lever to close the contact in the solenoidvcircuit, tihus opening the inlet valve and preventing the flow of feedwater into the boiler. Temperature operated meansare also provided forclosing the solenoid circuit and will be described hereinafter, thepressure operative means serving to close the solenoid circuit not onlyon an increase in pressure due to steam genera tion but also due to thepressure created by the feed pump, as for instance when the vehicleistraveling down a long grade, and the engine is turning over, operatingthe feed pump.= I

Means are also rovided for shutting ofi lid the fuel supply entirely'and'for opening the circuit of the'motor 7 when the pressure within theboiler reaches "a predetermined excessive value. Disposed in the fuelline 5'is a chamber'53 through which the fuel passes. The outlet fromthis chamber is controlled by a valve v54, to the stem of which issecured a core 55, surrounded by a solenoid 56. The solenoid circuitis'normally closed, so that the valve 54 is normally held in the raisedposition, permitting the flow of fuel. When the solenoid circuit is 0ened the valve falls, cuttin oil the supply oi fuel to the burner and Won the circuit is subseqiiently closed, the valve is again raised.

61. Passing through the lever 61 is an adjusting screw 62, the lower endof which lies in the path of the disc 63, adjustably secured to the rod33. When the rod is raised, the disc contacts with the lower end of thescrew 62 and raises the lever 61 to open the solenoid circuit. Bindingposts c4. and 65" for the contacts 58 and 59 respectively are arrangedon the exterior of the casing 32. The screw 62 is provided with a milledhead 66 which is engaged by a spring 67 to hold the head againstaccidental rotation after the. screw has been moved to the propersetting.

Secured to the stem of the fuel valve 54 is a contact 68 which isnormally in contact with a fixed contact 69, both contacts being in thecircuit of the emotor 7. When the valve 54 drops to close the fuelsupply, the contacts 68 and 69 are separated, opening the motor circuit.

Disposed in the circuit of the solenoid 56 is anormally closed breakcomprising the contact 71 and 72. The contact 72 is stationary and thecontact 71 is carried by an insulator disc 73 secured to a metallic rod74 capable of varying its length under changes in temperature. The rod74: is disposed in a metallic tube 75, having a lesser coefficient ofexpansion and preferably dis posed within one of the boiler tubes. vT hetube 7 5 is closed at its inner end and the rod is secured to the tubeat its inner end.

' The rod is, therefore, subjected to boiler valve 42 open when thetemperature in the boiler is low, to prevent flooding the boiler. Thesolenoid 43 is provided with a circuit 7 6, in parallel with thepressure controlled circuit, and the circuit 76 contains a break whichis closed until the boiler temperature.

increases to apredetermined value. The disc 73 carries a contact 77,which, when the boiler is cold, contacts with the fixed contact 78 inthe circuit 76, energizing the solenoid 43 and holding the valve open.When the temperature increases, the contacts are separated, the valve 42is released and feed water is pumped into the boiler.

The motor 7 and the solenoids are ener-- gized by current from thestorage battery 7 9, which is grounded on'one side and which I heatabsorbing medium in which the pressure may be made to vary by anapplication of heat, a .valve for varying the amount of air supplied tothe burner, a valve for varying the supply of fuel to the burner, meansresponsive to the pressure of the heat absorbing medium for mechanicallyoperating the air valve, and means responsive to the movement of the airvalve for operating the fuel valve.

2. In a control system for a steam power plant, aliquid fuel burner foraffecting a heat absorbing medium in which the pressure may be made tovary by an application of heat, a valve for varying the amount of airsupplied to the burner, a shaft connected to-the valve, means responsiveto the pressure of the heat absorbing medium for operating the shaft, avalve for varying the supply of fuel to the burner, and a mechanicalconnection between the shaft and this latter valve.

3. In a control system for a steam power plant, a liquid fuel burner foraffecting a heat absorbing medium in which the pressure may be made tovary by an application of heat, a rotary valve for varying the amount ofair supplied to the burner, means responsive to the pressure of the heatabsorbing medium mechanically connected to this valve, a valve forvarying the supply of fuel to the burner, and a direct mechanicalconnection between the two valves.

4. In a control system for a steam power plant, a liquid fuel burnerfor'afi'ecting a heat absorbing medium in which the pressure may be madeto vary by an application of heat, a rotary shaft, a' valve fastened tothe shaft for varying the amount of air supplied to the burner, meansresponsive to the pressure of the heat absorbing medium for rotating theshaft, a valve for varying the supply of fuel to the burner, and a crankeorlinectionbetween the shaft and the fuel va ve.

5. In a control system for a steam power plant, a liquid fuel burner foraffecting a heat absorbing medium in which the pressure may be made tovary by an application of heat, a blower for supplying air to theburner, an electric motor for driving the blower, a valve forcontrolling the supply of fuel to the burner, means responsive to a risein pressure in the medium for operating the valve so as to interrupt theflow of fuel, and

means responsive to the operation of this valve for rendering the motorinoperative.

6. In a control system for a steam power plant, a liquid fuel burner foraffecting a heat absorbing medium in Which the pressure may be made tovary by an application of heat, a blower for supplying air to theburner, an electric motor for driving the blower, a valve forcontrolling the supply of fuel to the burner, an electromagnet foroperating the valve, an electric control circuit for the"magnet, meansresponsive to a rise in pressure in the medium'for altering the circuitso as to cause the valve to interrupt the .supply of fuel, an electriccircuit for the motor, and means operated by the electromagnet forcontrolling the motor circuit.

7. In a control system for a steam power plant, a liquid fuel burner foraffecting a heat absorbing medium, a blower for supplying air to theburner, an electric motor for driving the blower, a valve forcontrolling the supply of fuel to the burner, means responsive to a risein temperature in the medium for operating the valve so as to interruptthe flow of fuel, and means responsive to the operation of this valvefor renderin the motor inoperative.

8. In a control system for a steampower plant, a liquid fuel burner foraffecting a heat absorbing medium, a blower for supplying air to theburner, an electric motor' for driving the blower, a valve forcontrolling the supply of fuel to the burner, an electromagnet foroperating the valve, an electric control circuit for the magnet, meansres onsive to a rise in temperature in the me ium for altering thecircuitsoas to cause the valve to interrupt the supply of fuel, anelectric circuitfor the motor, and means operated by the electromagnetfor controlling the motor circuit.

9. In a control system for a steam-power msmeo plant, a liquidfuelburner for affecting av heat absorbing medium in which the pressuremay be made to vary by an application of heat, a valve for varying thesupply of fuel to the burner, a valve for abruptly interrupting thesupply of fuel, and means responsive to a rise in' pressure forgradually closing the first valve and later for operating the secondvalve.

10. In a control system for a steam power plant, a liquid fuel burnerfor affecting a heat absorbing medium, a valve for gradually varying thesupply of fuel to the burner, another valve for abruptly interruptingthe supply of fuel, and means responsive to a rise in temperature of themedium for gradually closing the first valve, and later for operatingthe second valve.

11. The combination with a heat absorbing medium containing device, of aliquid fuel burner associated with said device, a conduit througlf whichair is introduced into said burner, a valve arranged to vary the flow ofair through said conduit, a spring loaded piston subjected to thepressure in said device and connected to said valve, a conduit throughwhich fuel is in-' operative by further movement of the air valve foroperating said second fuel valve.

12. The combination with a heat absorbing medium containing device, of aliquid fuel burner associated with said device, a

conduit through which fuel is introduced into the burner, a valve insaid conduit adapted to vary the flow of fuel therethrough, a secondvalve in said conduit adapted to abruptly halt the fiow of fueltherethrough, means operative by an in creasing pressure in the devicefor gradually closing said first valve and then abruptly closing saidsecond valve.

13. The combination with a heat absorbing medium containing device, of aliquid fuel burner associated with said device, a

conduit through which fuel is introduced into the burner, a valve insaid conduit adapted to vary the flow of fuel therethrough, a secondvalve in said conduit arranged to abruptly open and close said conduit,a solenoid for operating said second valve, and means operative by anincreasing 5 pressure in the device for gradually closing said firstvalve and then noid circuit.

14. The combination with a heat absorbing medium containing device, of ali uid. fuel burner associated therewith a con uit opening thesolethrough which fuel flows to said burner, a T

casing to which said conduit is connected, a means actuated byvariations in pressure valve in said casing for controlling the flowwithin the device for moving said rod. 10 of fuel through said conduit,a rod en ag- In testimony whereof, I have hereunto set ing said valve, asecond valve in the con uit, my hand at San Francisco, California, thisa solenoid for operating said valve, a circuit 6th day of December,1919.

for said solenoid, normally engaging con- JESSE W. DOBLE. tacts in saidcircuit disposed in said casing .In presence ofadapted to be separatedby said rod, and H. G. Pnosr.

